I’ve recommended Edward Tufte’s books many times… you can see some of my previous comments here and here.
He’s going to be in Atlanta next month. If your job consists of presenting complex information on paper or on screen, you should go: <http://www.edwardtufte.com/tufte/courses>. People travel from all over the country (world?) to attend these one-day seminars. If you’re reading this blog from anywhere in the Southeast, you have no excuse for not taking advantage of the day!
Disclaimer: I have no relationship with Tufte other than having shaken his hand after the Atlanta course a few years ago; I don’t make a dime if you sign up. If going to the course isn’t convenient for you and all you want is the books, buy them from the links below and I’ll make a buck per book.